Chatan Castle: A Ryūkyūan Fortress and Sacred Complex in Japan
Site at a Glance
- Rating
- 4
- Popularity
- Very Low
- Country
- Japan
- Primary era
- Medieval
- External website
- Open
- Eras represented
- Medieval, Modern
- Civilizations
- Kingdom of Chuzan
- Site type
- Military
- Remains
- Castle
On this page22 sections
History
Chatan Castle, also known as Chatan Gusuku, is a Ryūkyūan fortress and sacred complex in Japan, on Okinawa Island. Built and expanded by local lords within the political world of Chūzan, one of the principal medieval powers of the Ryūkyū Islands, it became an important stronghold from the second half of the thirteenth century and remained in use into the early seventeenth century. Its surviving remains belong chiefly to the fourteenth and fifteenth centuries, when the fortress served as a centre of local authority.
Before and during the Gusuku period
The limestone hill was occupied by a village during the transition from the pre-agricultural Late Kaizuka period to the agricultural Gusuku period, before and during the twelfth century. The Late Kaizuka period preceded the Gusuku period in Okinawa, while the later period saw the growth of more centralized agricultural communities and fortified political centres. Excavated postholes and pottery indicate that activity on the hill began before the main fortress was formed.
Chatan Castle was probably constructed gradually by successive local lords between the thirteenth and fourteenth centuries. No contemporary record describes its foundation, so the earliest history survives mainly through later oral traditions and genealogies. The first lord is traditionally called Kaniman Aji. An aji was a local lord or regional aristocratic ruler, and the title Kaniman is associated with ironworking during the early Gusuku period. A genealogy published in 1933 connects Kaniman Aji with the reign of King Eisō, dated 1229 to 1299.
Tradition describes a series of struggles among powerful local families. The last Kaniman Aji was defeated by Ūkā Aji, also called Ōkawa Aji. Ūkā Aji was then defeated by Tancha Ufunushi, before Ūkā Aji’s son recovered power with help from his father’s former followers. These events form the subject of The Revenge of Ōkawa, a kumiodori play in the classical Ryūkyūan musical theatre tradition. Since Kaniman Aji and Ūkā Aji were hereditary titles, the number of generations involved is uncertain. Genealogies claiming descent from both have led to the theory that the two figures belonged to one family, or may even have been the same person.
Power under the Ūkā Aji family
The names Ūkā Gusuku and Ōkawa Gusuku derive from Ūkā, meaning “large river,” an alternate name for the Shirahi-gawa River. The Ūkā Aji family appears to have been the principal builder of the fortress during the fourteenth and fifteenth centuries and was probably especially powerful. Around 1500, during the reign of King Shō Shin, the lord of Chatan Magiri was called Chatan Aji, and sometimes Chatan Ōkawa Aji. A direct descent from the Ūkā Aji family, however, has not been established.
The fifteenth volume of the Omoro Sōshi, a major seventeenth-century collection of songs and poems from the Ryūkyū Islands, was compiled in 1623. It calls the lords of Chatan “the sun of Chatan” and “the world-lord of Chatan.” Similar expressions in the collection are often applied to kings. The particular Aji referred to cannot be identified, but the language suggests that Chatan’s lords were regarded as unusually powerful.
Chatan Castle worked together with Ichi Gusuku, an outpost on the opposite bank of the Shirahi-gawa River. The fortress appears to have lost its role as a regional administrative centre after Chatan Banju, a guardhouse, was built at the foot of the hill in the late fifteenth century. It was deserted as a fortress several decades later in the sixteenth century, although parts of its land were subsequently cultivated.
The 1609 invasion and later religious use
Chatan Castle still had a military role during the 1609 invasion of the Ryūkyū Kingdom by forces from Satsuma, a domain of southwestern Japan. The invasion brought the kingdom under Satsuma’s political control while leaving its royal institution in place. The fortress was defended by Yō Chōhō Sashiki Chikudun Kōdō, who continued resisting until he learned that Shuri had fallen. He then committed suicide, and his tomb lies on the northern cliff. Ichi Gusuku also played an important part in the resistance.
After 1609, Chatan Castle was no longer used as a fortress, but it continued as a religious centre and became an important funerary area. Eighty-two tombs have been identified across the hill. Local tradition says that in 1821 stones from the castle walls were used to rebuild Ichi Gusuku Bridge, and they may also have been used for Machinato Bridge.
The castle was associated with the settlements of Chatan, Tamēshi, and Rindō south of the hill. Sacred places connected with those communities remained in use until the land was seized after the Second World War. Agari-nu-utaki, a utaki or sacred site, was traditionally used as an altar for directing prayers toward Yanbaru Kubō Utaki, probably the Kuba Utaki at Nakijin. A substitute altar was established at the Chatan Chōrōyama Ritual Complex in 1960. Permission to rebuild sacred places within the military area was granted in 1993, but Agari-nu-utaki could not be reconstructed at its original location and was rebuilt in the southern part of the third enclosure. It received municipal folk-cultural-property designation in 2004.
The Tun sacred site was associated with Chatan and Tamēshi. The Chatan Noro, a female ritual official responsible for important community rites, used it during rice-ear and rice-harvest festivals, when local administrators and villagers brought offerings. Tun was rebuilt in 1993 in the southwestern part of the third enclosure, about 15 metres northeast of its original position, and was designated a municipal folk cultural property in 2004.
Iri-nu-utaki was rebuilt in December 1993 in the fourth enclosure. Its original location is disputed between the third and fourth enclosures, although the fourth is considered more probable. Before the Second World War, the Chatan Noro normally controlled entry, except before the Chatan tug-of-war, held every thirteen years, when villagers were permitted to pray for the festival’s safe conduct. The Gusuku Hi-nu-kan, or gusuku fire-god site, stands before Iri-nu-utaki. Prayers were offered there before people entered the sacred area.
The Chatan Sū-gā spring on the western edge of the hill supplied everyday water and sacred New Year water. Inagu-gā was used by the fortress’s female attendants for bathing and laundry, while Nūru-gā was used by the Noro for purification. Kagan-gā was represented by an incense burner in the third enclosure near Tun and Agari-nu-utaki. Rituals continue at Agari-nu-utaki and Tun during the Umachī festivals in the fifth and sixth lunar months, and at Sū-gā during first-prayer and spring-prayer observances.
War, military occupation, and archaeological investigation
After the Second World War, U.S. forces seized the hill and incorporated it into Camp Zukeran, later Camp Foster. Two smaller eastern hills were levelled, the western end of the main hill was cut back for National Route 58, and the surrounding landscape was extensively altered. Japanese forces also cut at least five military tunnels into the northern cliff during the war.
Archaeological research began in 1957, when U.S. personnel installing a water tank discovered the Chatan Gusuku Shell Mound. The mound was described in 1960. In 1979, former members of the University of the Ryukyus Archaeological Club identified seven sites on and around the hill. A month-long topographic survey in August 1982 identified four stone walls and three levelled areas that defined enclosures. A field survey in October established the extent of the fortress, identified eighty-two tombs, and recorded the wartime suicide-boat tunnel complex. It also identified fifty-one plant species.
Reconnaissance in 1992 and 1993 confirmed twelve archaeological sites within the fortress. Nineteen archaeological investigations followed the 1982 survey between 1984 and 2019. They included excavations in the first through fourth enclosures, research into the former Rindō settlement and its route toward the castle gate, surveys of the stone walls, and a 60,000-square-metre survey in 2018 and 2019 that produced a detailed map. The site was returned to Japan on 31 March 2020, although access remains strictly controlled by the Japanese Defense Bureau. Chatan Gusuku became a National Historic Site on 20 November 2020, and Chatan Town has proposed a historical park presenting the archaeological remains.
Remains
Hill, walls, and enclosures
Chatan Castle occupies a natural Ryūkyūan limestone hill near the estuary of the Shirahi-gawa River. The ridge extends about 500 metres from east to west, is approximately 150 metres wide, and reaches a maximum elevation of 44.7 metres. The castle covers about 16,600 square metres. A northern cliff between 10 and 20 metres high, a two-tiered southern cliff, and the broad river at the foot of the northern slope provided natural protection. Two smaller hills once stood to the east and were connected to the main hill by a ridge. Excavations indicate that the sea reached inland to the foot of the hill during the twelfth century.
Five relatively well-preserved enclosures organize the fortress. Enclosures 1 through 4 extend from east to west, while Enclosure 5 lies north of Enclosure 4. The first enclosure is the highest, and the ground generally descends westward. Each enclosure is a levelled area separated by stone walls that fill spaces between natural limestone outcrops. The builders altered the natural landform only to a limited degree. Since limestone outcrops become less common in the lower enclosures, constructed walling increases toward Enclosure 4.
The walls use rubble masonry and carefully cut ashlar, with limestone or coral limestone. Some survive to about 1.5 metres high and reach widths of up to 9 metres. The eastern walls are generally better preserved. Three historically plausible approaches came from the south, north, and east, and each involved modifying the terrain to ease movement. The broad southern route was probably the official approach. It enters Enclosure 4, turns west, and reaches the probable main gate in the wall of Enclosure 3. The Chatan Noro used it to reach sacred places before the Second World War, giving it the name Noro’s Path.
Enclosure 1 and the eastern defences
Enclosure 1 is the highest and smallest enclosure, measuring about 40 by 20 metres, or approximately 800 square metres, at 44.72 metres above sea level. Much of its surface is exposed bedrock. The limestone was abraded to make a level surface, but the usable area is no more than 60 square metres. A small terrace lies to the north. Although the highest enclosure of a gusuku would normally contain the lord’s residence, no residential remains were found here, and its function remains uncertain.
A north-south wall about 25 metres long runs along the eastern side of the enclosure, the side not protected by a cliff. Its inner western face is built of rubble, while the outer eastern side has two ashlar faces. The wall may have been widened from about 6 to 9 metres, and its width suggests that it may originally have stood more than 4 metres high. About 50 metres east is an L-shaped depression, approximately 8 metres long, probably the remains of a defensive ditch. The ditch was cut during the Gusuku period and began filling during the sixteenth century after the fortress lost its administrative role. Small terraces descend toward the river and probably served defensive purposes.
Agari Gusuku, meaning “eastern gusuku,” is the neighbouring hill that may have helped protect the eastern wall. A water tank installed by U.S. forces now occupies it. Stone projectiles and iron arrowheads found along the eastern wall indicate fighting in this area. The boundary between Enclosures 1 and 2 consists mainly of limestone outcrops, supplemented on the south by a wall with cut-stone foundations. A depression about 1.5 metres wide and 1.5 metres deep has sometimes been interpreted as a water tank.
Enclosure 2 and the residential remains
Enclosure 2 covers approximately 1,500 square metres and measures about 30 by 50 metres. It slopes gently toward the southwest. Bedrock outcrops leave no more than 280 square metres of practically usable level ground, with a secondary terrace to the north. Excavated remains in the southern and eastern corners of the surrounding walls, together with substantial sections of the southwestern and southeastern walls, have been interpreted as the remains of the main residential building.
The southeastern wall has rounded corners. Its inner face retains coral-limestone ashlar, while only the foundation course survives externally. The western section uses limestone blocks about 80 centimetres long, and the eastern section uses coral blocks about 30 centimetres long. The southwestern wall contains limestone or coral blocks about 45 centimetres long. These limestone and coral sections rest on the same foundations, which were laid over compacted earth, and show no identifiable chronological difference. In several places only the foundations remain, probably because the upper cut stones were reused after the fortress was abandoned. The position of the enclosure gate is consequently uncertain.
Two Gusuku-period gravel pavements occupy the northwestern and southwestern corners. They are made from crushed table coral and massive coral, several centimetres across, which appears to have been broken on site. A stone alignment, postholes, and foundations also belong to the area interpreted as the main residence. The southern alignment consists of cut stones running perpendicular to the western wall and may relate to the enclosure gate.
The principal building remains include a 9.8-metre alignment of coral-limestone ashlar interpreted as a rainwater drain. North of it, limestone blocks were placed in a ground depression to level the surface and create foundations. Fourteenth- and fifteenth-century artefacts are concentrated in this area. Beneath the blocks is a layer of charcoal, ash, burnt stones, and broken artefacts, showing that the fortress was destroyed by fire at least once. The deepest cultural layer contains postholes about 50 to 60 centimetres in diameter and 30 centimetres deep, many with post moulds or packing stones. They belong to an earlier occupation exposed where later fortress remains were not present. Second World War shelling damaged the northern gravel pavement.
Enclosure 3 and sacred places
Enclosure 3 measures approximately 40 by 80 metres, or 3,200 square metres. A cliff about 2 metres high separates it from Enclosure 2. It contains fewer bedrock outcrops, leaving most of its surface sufficiently level for use. Its western side has earth deposits up to 1.8 metres thick, spread to level the ground near the wall separating Enclosures 3 and 4. The deposits contain abundant locally made flat-constricted-bottom pottery and little celadon or porcelain, probably dating from the rise of local ajis in the second half of the thirteenth century.
The western corner produced early Chinese blue-and-white porcelain and Chinese coins, including one minted between 1102 and 1106. Most celadon belongs to the fourteenth and fifteenth centuries, with a few pieces from the Southern Song period. Charred barley, wheat, and rice dating from the thirteenth and fourteenth centuries indicate another destruction by fire. Fourteenth- and fifteenth-century pottery, celadon, and brown-glazed Nanman stoneware also occur in the fourth enclosure, probably at the same time as the residential building in Enclosure 2 and the upper occupation layer in Enclosure 3.
Two gates have been investigated. The principal gate lies at the southern corner, while a riverside gate occupies the western corner. The cliff between Enclosures 3 and 4 is 3 to 4 metres high, and the dividing wall has two projections extending into Enclosure 4. The northern wall above the Kaniman Aji tomb uses rubble masonry. The southern approach includes Noro’s Path, a squared level area enclosed by a stone wall, an artificial slope with possible steps, and several stone pavements.
The central squared area has a pavement of limestone cobbles about 10 centimetres across, together with incense burners and ceramic alcohol bottles. It has been identified as Gusuku-nai-nu-tun, a sacred site under the authority of the Chatan Noro. An artificial slope connects it with the southwestern corner of the wall around Enclosure 2. Parallel stone alignments may be steps leading toward the main enclosure and align with the feature possibly associated with the Enclosure 2 gate. A rough limestone structure projects into Enclosure 3 from this corner, although its function is uncertain.
A second pavement in the southern part of Enclosure 3 consists of tightly compacted coral fragments and shells, 2 to 3 centimetres across, mixed with earth. It is interpreted as a path leading to a building represented by postholes along its northern side. The principal gate between Enclosures 3 and 4 lay west of this pavement.
Enclosure 4 and the military area
Enclosure 4 is approximately 96 by 100 metres, covering about 9,600 square metres and making it much larger than the other enclosures. It probably served a military purpose, providing space to assemble troops and supplies during an attack. Excavation in 1987 showed that its level surface was created with stone fill. Stones about 20 centimetres across were used beside the cliff, while stones about 10 centimetres across were used on the hillside.
The western and eastern parts differ in elevation by about 10 metres. They may represent two separate enclosures, which would raise the total to six, but this possibility remains unconfirmed because the western area, called Iri Gusuku, is a sacred place closed to men and has not been excavated. A rubble wall ran along the cliff on the western side of the levelled area. Later excavation exposed 10 metres of the southern wall west of the main gate in ashlar masonry, while elsewhere only roughly stacked, uncut limestone blocks survive.
Near the eastern walls, investigators found two walls running east to west for about 25 metres. One is 6 metres wide and made of roughly cut stones; the other is 9 metres wide and built from carefully cut ashlar. Both have rounded corners. The principal gate lies in the southern wall between Enclosures 3 and 4. Its foundations occupy a level area slightly below the rest of Enclosure 3. The gate was about 2 metres wide and closed with a wooden door. Steps on the slope in Enclosure 4 indicate the approach path.
Enclosure 5 and the northern route
Enclosure 5 is a terrace north of Enclosure 4, approximately 75 by 20 metres, or 1,500 square metres. It was recognized as a separate enclosure during a 2019 reconnaissance survey. A large limestone boulder that fell from the cliff occupies the terrace, and its top was levelled with coral gravel. An indentation in the cliff about 5 metres above the boulder probably marks an overhanging northern gate.
The northern route passes through Enclosure 5. It is steep enough for only one person at a time, and artificial platforms and slopes helped people climb it. A ladder may have been required. The route reaches the northwestern corner of Enclosure 3 and may have led to the overhanging gate. Because it was the most direct route from the river, it was probably an important entrance for trade. The eastern route was broader and led from the neighbouring eastern hill directly to Enclosure 1, although much of it was destroyed by postwar alterations.
Tombs and funerary remains
Kaniman Aji tomb
The tomb traditionally attributed to Kaniman Aji lies in a natural cave on the northern slope within Enclosure 5. The opening is about 3 metres wide and 5 metres high, with its lower section closed by an ashlar wall. The funerary chamber measures approximately 8 by 6 metres and is 6 metres high. A stone-stepped haka-michi, or tomb path, once ran from the top of the hill through the fortress.
The cave contained many human bones when it was used as a wartime refuge, suggesting that it was a collective tomb. A stele identified it as the sacred tomb of the historical lords of Chatan Castle, Kaniman Aji, implying that several generations who held the title were buried there. People from surrounding villages used the tomb for Shīmī prayers until the Second World War. After the war it was emptied and relocated outside the military base in 1960. It is not currently used.
Kōdō and Chatan Mōshi tombs
The tomb attributed to Yō Shiho Sashiki Chikudun Kōdō lies about 10 metres west of the Kaniman Aji tomb, also within a natural cave. Its entrance is closed with rubble masonry and has a small forecourt. A stone stele once stood there, but only its foundations remain. The attribution rests on historical references to a stele at Kōdō’s tomb.
The tomb of Chatan Mōshi lies about 10 metres west of Kōdō’s tomb and has been severely damaged by landslides. Chatan Mōshi was a celebrated singer whose story was dramatized in a play bearing her name.
Cliff tombs
Two unnamed tombs occupy adjacent natural caves on the cliff facing the Shirahi-gawa River. Their opening is about 2.5 metres wide and 1.3 metres high, while the caves extend about 1.8 metres into the cliff. Four circular holes, approximately 15 centimetres across, were cut into the ground, ceiling, and entrance area. These held wooden beams used to close the tombs.
Archaeological sites and finds
Reconnaissance identified eleven archaeological sites on the hill, including the Kaniman Aji tomb, the tomb attributed to Kōdō, Chatan Mōshi’s tomb, the two unnamed cliff tombs, pottery scatters and refuse deposits, the former Rindō settlement, and the Chatan Gusuku Shell Mound. The Fensa-kasō pottery scatter at the northwestern foot of the hill belongs to the Late Kaizuka period. A southwestern scatter associated with Sū-gā contains Kaizuka pottery and early-modern stoneware, while the former Rindō settlement produced early-modern stoneware, porcelain, and celadon.
A scatter below the southern cliffs of Enclosures 1 through 3 contained Late Kaizuka and Gusuku-period pottery with abundant celadon. An Early Kaizuka Phase III scatter in the northeast was destroyed before or during the 1993 excavation. A southeastern scatter contained Late Kaizuka pottery and marine shells and may form part of the Chatan Gusuku Shell Mound. Several former hills south of the castle, including Rindō, Tamēshi, Mēgusuku, and Chōrōyama, also yielded Gusuku-period material and were closely connected with Chatan Castle.
Archaeological work recovered 30,970 artefacts, mainly from Enclosures 2 and 3. Most are pottery fragments, followed by imported celadon and brown-glazed stoneware. The collection also includes roof-tile pottery, Chinese white porcelain, imported stoneware, Chinese blue-and-white porcelain, Jian ware, Kamuiyaki ware, iron and bronze objects, and coins. Some roof-tile fragments bear impressed floral decoration dating from the fourteenth to the sixteenth century.
Only a few celadon fragments date from the Southern Song period. Most belong to the fourteenth and fifteenth centuries, as does all the Chinese white porcelain. A few Yuan to early Ming blue-and-white porcelain pieces from Enclosure 3 are rare in Okinawa and point to the probable power of Chatan’s Aji. Five Chinese coins were found in Enclosure 2, including complete examples minted in 1189 and during the second half of the fourteenth century. Another coin, minted between 1102 and 1106, came from Enclosure 3. Iron objects include nails, pins, and projectile points. The distribution of the artefacts indicates especially intensive occupation during the Late Kaizuka and Gusuku periods, with little material from the beginning of the Gusuku period or after the sixteenth century.
Reconstructed sacred places
Agari-nu-utaki and Tun
Agari-nu-utaki now stands in the southern part of Enclosure 3, while survey markers indicate its original position. A sacred stone beside the reconstructed shrine served to direct prayers toward Nakijin Kubō Utaki. Tun was reconstructed in the southwestern part of the enclosure, about 15 metres northeast of its former location. The present site includes the ritual area identified archaeologically as Gusuku-nai-nu-tun.
Iri-nu-utaki and Gusuku Hi-nu-kan
Iri-nu-utaki stands in Enclosure 4 in the area called Iri Gusuku. It contains thirteen incense burners, commonly called “the thirteen gods” or “the thirteen incense burners.” A stele at the entrance states that men are forbidden to enter the sacred enclosure. Gusuku Hi-nu-kan stands in front of it and served as the fire-god site where prayers were offered before entry.
Sū-gā and Kagan-gā
The Sū-gā well on the western edge of the hill is enclosed within a concrete shrine. An incense burner stands behind it, accompanied by two other burners and associated stone steles. In Enclosure 3, an incense burner and stele for Kagan-gā stand near Tun and reconstructed Agari-nu-utaki. The stele records the relationship with Agari-nu-utaki and indicates that the burner was installed in 2005.
Associated settlements and Ichi Gusuku
Ichi Gusuku lies about 500 metres northwest across the Shirahi-gawa River. It was regarded as Chatan Castle’s outpost and participated in the resistance to the 1609 invasion. Oral tradition alternatively calls it the castle’s storehouse. Its hill, sacred places, and tombs were destroyed or relocated after the war during construction of the road that became National Route 58. The eastern foot of the truncated hill remains visible beside the river.
Kumuibaru and Kushikanikubaru, on the opposite riverbank, were early Gusuku-period settlements and cemeteries. Their large quantity of imported material suggests that they were more active centres than Chatan Castle at the beginning of the Gusuku period. Together with Rindō, Tamēshi, Mēgusuku, and Chōrōyama, these associated places form the wider settlement and ritual landscape connected with the fortress.
Nearby sites
